went through similar ordeal trying to buy specific size bf goodrich tyres for my 4wd, so i just ordered from tirerack
the michelins would work well on stock 20s, get rid of the runflats, much improved ride comfort without them
i would consider them if they made more sizes in 21. but atm the closest fronts are 2.7% out, and my yoki's are 0.0% front and 0.2% out on rear